Gigabyte to support four SLI graphics cards on one motherboard
 

If even two graphics cards in your PC are not enough, what about four? SLI typically is limited to two cards within one system, but sources told Tom's Hardware Guide that Gigabyte will soon offer a "Quad" motherboard with slots for up to four Nvidia-based SLI cards.

http://www.tomshardware.com/hardnews...26_155843.html

how will the drivers know there are 4 cards?

nvidia will be more than happy to change their drivers to support that, just to have that bit of more performance compared to ati and being able to brag about it